Swinging knife die for a staying machine



. July 28, 1964 a. a. SPEIDEL- swmcmc KNIFE DIE FOR A STAYING MACHINE Filed Dec. 18, 1961 INVENTOR. GEORGE B. SPEI DEL FIG. 2.

ATTORNEYS United States Patent 3 142 066 SWINGING KNIFE DB FOR A STAYING MACHINE George B. Speidel, Cheltenham, Pa., assiguor to Metal Edge Industries, Barrington, N.J., a corporation of New ersey Filed Dec. 18, 1961, Ser. No. 159,936 2 Claims. (Cl. 1--117) This invention relates to an improvement in a swinging knife die for a staying machine.

It is well-known to employ a swinging knife die for a staying machine wherein the knife is provided with a cutting portion to sever a metal stay and a V-shaped portion which is aligned with the V-shaped groove of the die by swinging the knife after the stay is cut off by the cutting portion. Such a structure is shown, for example in United States Patent No. 2,987,728. While generally satisfactory, swinging knife dies have a deficiency when it is desired to achieve very accurate placement of the metal stay on a corner structure such as the corner of a box. When the knife cuts off the stay which is of spring metal, the cut end of the stay adjacent to the knife snaps upward and forward in the structure supporting it and during the interval between cut off and the engagement of the prongs of the stay with the box, this end of the stay tends to assume a misaligned position. It will be noted that such misalignment does not occur in staying machine dies which do not employ a swinging knife since the cut off of the stay and the engagement of the stay prongs with the box are substantially simultaneous. In the case of a swinging knife die a substantial interval occurs between cut off and the engagement of the stay prongs with the box due to the necessary time interval which must be provided to swing away the cutting portion and align the V-shaped portion of the knife with the V-shaped groove of the die.

In accordance with this invention, the above-discussed problem has been solved by providing means to bias the stay down against its support. A marked improvement in accuracy and consistency in placement of stays on boxes is achieved.

The invention will be further clarified by reading the following description in conjunction with the drawings in which:

FIGURE 1 is a vertical section partially broken away of a staying machine die incorporating the improvement of this invention;

FIGURE 2 is an elevation of the staying machine die of FIGURE 1 as viewed from the right-hand end;

FIGURE 3 is a vertical section partially broken away taken on the plane indicated by the line 33 in FIG- URE 1; and

FIGURE 4 is a view taken on the plane indicated by the line 4-4 in FIGURE 3.

As shown in the drawings, a die 2 in accordance with this invention is provided with a die body 4 having an upper key portion 4 which is adapted to be engaged by the key-way of the cross-head of a staying machine (not shown) as is conventional in the art and shown, for example, in Patent No. 2,070,767. Die 2 has a lower portion 5 provided with a V-shaped groove 6. The several portions of the die 2 are bolted together by means of bolts indicated at 7. Each gib 8 is retained by a plate 9 attached to die 2 by screws 10 carrying rollers 10A. Each gib 8 has an open portion 11 containing a leaf spring 12 lying below a pin 13 secured to plate 9 to bias gib 8 downwardly.

A stay cut-off mechanism indicated generally at 14 has a cutter slide 16 comprised of adjacent members 17 and 18. Cutter slide 16 is biased downwardly by means of compression coil springs 20, 20 which are engaged in openings 22, 22 in member 17 and openings 24, 24 in member 26. Member 26 is pivotally mounted on reduced portion 28 of a pin 30 which is secured to die 2 by a pressed fit. Member 26 is retained by a nut 31. The downward travel of the slide 16 is limited by a pin 32 secured .to member 17 by a pressed fit and which engages a U-shaped slot 34 in retaining plate 36. Retaining plate 36 engages the outer face of slide 16 and is secured to die member 2 by means of bolts 38, 38 and a pair of compression springs 40, 40 interposed between retaining plate 36 and the heads of bolts 38. Member 18 of cutter slide 16 is provided with a slot 41 through which a metal stay 42 is adapted to pass and a V slot 43 for engage ment of an anvil. Slot 41 has an edge 44 which is adapted to cooperate with a knife to be described in order to sever stay 42.

Stay 42 is supplied by a throat indicated at 46 in a conventional manner, throat 46 being secured to cutter slide 16 by bolts indicated at 48.

A knife 60 is pivotally secured to pin 30 at 62. Knife 60 is provided with a straight cutting edge indicated at 63 and an adjacent V-shaped portion 64 which is adapted to become aligned with V-shaped slot 6 of die 2. Knife 60 has a cam opening'66 which is engaged by a cam follower 70. Cam follower 70 is mounted on a pin 72 which is secured by a pressed fit to a block 74. Block 74 is mounted by a pressed fit in a groove 76 in cutter slide 16 and acts to secure adjacent members 17 and 18 of the cutter slide together. Block 74 is held by a pin 19 secured to block 74 and member 17 by a pressed fit. Cam follower 70 is adapted to move vertically in a slot 80 in plate 82 which is interposed between die 2 and knife 60. Die 2 is provided with a recessed portion 84 to provide for the unhindered movement of pin 72 and cam follower 70.

The knife 60 is fiat on both sides and the oppositely presenting faces thereof engage respectively with the adjacent flat faces of members 18 and 82.

The above described staying machine die is old in the art and is disclosed in United States Patent No. 2,987,728 mentioned above, with the exception of the above described gibs which are well known. The disclosure of Patent No. 2,987,728 is incorporated herewith.

Operation of Old Structure In operation stay 42 in the desired length is fed into the die 2 and is supported on gibs 8 as best seen in FIGURE 3. The die and its associated mechanism is then forced downwardly against an anvil which supports a box which is to he stayed. Gibs 8 engage the box on the anvil and move outwardly and upwardly against springs 12 to clear and release the stay. The V slot 43 of cutter slide 16 engages the box and prevents further downward travel of the cutter slide. Die 2 continues to move downwardly which results in knife edge 63 shearing stay 42 where it emerges from slot 41 in cutter slide 16. It will be appreciated that the shearing operation is accomplished quickly after slot 43 engages the box and before the position of knife 60 is shifted.

As die 2 continues in its downward movement, carrying with it knife 60, cam opening 66 is moved so that it engages cam follower roller 70, causing knife 60 to be swung to the left, placing V-shaped portion 64 in line with the V-shaped groove 6 of die 2. Thus, when die 2 forces stay 42 to the box, knife 60, rather than presenting the cutting edge 63 presents the V-shaped portion 64 which will act to secure the end of stay 42 to box 92.

As the die is carried back upwardly, springs 20 force cutter slide 16 downwardly until pin 32 engages slot 34. As cam follower 70 moves downwardly with respect to die 2, it restores the cutting edge 63 to its operative position. Gibs 8 move to their original position ready to support another length of stay 42.

Improvement In accordance with this invention, a plunger 90 projects downwardly through a bore 92 in lower portion 5 of die 2 and extends into V-shaped groove 6 to engage the upper surface of stay 42. The upper end of plunger 90 is threaded as indicated at 94 and has secured thereto a pair of lock nuts 96 and 98 intermediate the threaded portion. The upper end of plunger 90 is received in an opening 100 in key portion 4 of die 2. Opening 100 also contains a compression coil spring 192 which engages nut 93 and acts to bias plunger downwardly to the point Where nut 96 engages lower portion 5 of die 2.

Operation Improvement Plunger 90 being in engagement with stay 42 biases stay 42 into engagement with gibs 8. During the cut-01f step when knife 62 cuts off stay 42, the stay 42 in the die will move upwardly somewhat against the bias of plunger 90 but, in the interval knife 60 is being swung to position V-shaped portion 64 to engage the box, the plunger 90 will have stabilized the stay 42 downwardly against gibs 8 to insure accurate positioning of the stay on the box.

It is not desired to be limited to the subject matter except as set forth in the following claims.

What is claimed is:

1. In combination with a swinging knife die for a staying machine having a V-shaped groove in the body portion thereof to embed a stay in a corner structure and having a swinging knife at one end thereof with a cutter portion to cut off a stay and a V-shaped portion which is aligned with the V-shaped groove of the body by swingring the knife after the stay is cut off, the improvement comprising:

a plunger mounted in said die in a recess opening into the apex of said groove at a point adjacent the end of the die adjacent the swinging knife,

resilient means biasing the plunger outwardly to continuously engage a stay in the die,

said plunger being movable entirely into said recess responsive to the relative upward movement of the stay into said apex on the securing of the stay to a corner structure by the die,

whereby the plunger maintains the stay in a predetermined position during the cutting off of the stay and the securing of the stay to a corner structure.

2. The combination of claim 1 having stop means to limit the outward movement of the plunger to the point of contact with the stay.

References Cited in the file of this patent UNITED STATES PATENTS 799,839 Eberle Sept. 19, 1905 1,417,609 Krorner May 30, 1922 2,987,728 Speidel June 13, 1961 

1. IN COMBINATION WITH A SWINGING KNIFE DIE FOR A STAYING MACHINE HAVING A V-SHAPED GROOVE IN THE BODY PORTION THEREOF TO EMBED A STAY IN A CORNER STRUCTURE AND HAVING A SWINGING KNIFE AT ONE END THEREOF WITH A CUTTER PORTION TO CUT OFF A STAY AND A V-SHAPED PORTION WHICH IS ALIGNED WITH THE V-SHAPED GROOVE OF THE BODY BY SWINGING THE KNIFE AFTER THE STAY IS CUT OFF, THE IMPROVEMENT COMPRISING: A PLUNGER MOUNTED IN SAID DIE IN A RECESS OPENING INTO THE APEX OF SAID GROOVE AT A POINT ADJACENT THE END OF THE DIE ADJACENT THE SWINGING KNIFE, RESILIENT MEANS BIASING THE PLUNGER OUTWARDLY TO CONTINUOUSLY ENGAGE A STAY IN THE DIE, SAID PLUNGER BEING MOVABLE ENTIRELY INTO SAID RECESS RESPONSIVE TO THE RELATIVE UPWARD MOVEMENT OF THE STAY INTO SAID APEX ON THE SECURING OF THE STAY TO A CORNER STRUCTURE BY THE DIE, WHEREBY THE PLUNGER MAINTAINS THE STAY IN A PREDETERMINED POSITION DURING THE CUTTING OFF OF THE STAY AND THE SECURING OF THE STAY TO A CORNER STRUCTURE. 